This invention relates to novel acetal-containing and aldehyde-containing monomers capable of homopolymerization and/or copolymerization with other monomers to give polymers containing acetal and/or aldehyde groups. It also relates to the preparation of the aldehyde-containing polymers from the corresponding acetal-containing polymers. It further relates to the use of the polymers as crosslinkable coatings, adhesives, and nonwoven binders.
Blocked aldehydes of unsaturated compounds have been described in various patents. Most of these relate to dialkyl acetals and diacetates of aliphatic aldehydes.
U.S. Pat. No. 2,417,404 (issued Mar. 11, 1947 to L. M. Minsk et al.) and U.S. Pat. No. 2,485,239 (issued Oct. 18, 1949 to E. F. Izard) describe the preparation and copolymerization of diacetates of olefinic aldehydes.
U.S. Pat. No. 4,191,838 (issued Mar. 4, 1980 to F. Merger et al.) describes acrylate and methacrylate esters of 2,2-dimethyl-3-hydroxy-propanaldehyde and U.S. Pat. No. 4,250,070 (issued Feb. 10, 1981 to G. Ley et al.) describe polymers prepared from these aldehyde-containing monomers. The polymers are cured (i.e., crosslinked) with hydrazine-containing derivatives which are known to be toxic.
U.S. Pat. No. 4.663.410 (issued May 5, 1987 to R. K. Pinschmidt, Jr. et al.) describes blocked aldehyde monomers from aliphatic amino-aldehydes.
U.S. Pat. No. 4,281,207 (issued Jul. 28, 1981 to J. C. Wilson) and U.S. Pat. No. 4,225,689 (issued Sep. 30, 1980 to J. C. Wilson et al.) describe vinyl aryl ethers of aromatic phenolic aldehydes. The aryl vinyl ethers are derived from vinyl benzyl chloride and a phenolic aldehyde which is not masked or blocked. This is known to cause problems during polymerization and copolymerization.
There is a need for crosslinkable acetal-containing polymers and for aldehyde-containing polymers wherein the method for introducing the aldehyde groups is not dependent on reaction with an aldehyde-containing monomer.